14.0 Instrumentation and Equipment
14.1 Radiation Detection Equipment
Authorized users must equip their laboratories with the appropriate survey instruments in good working order for each radioactive material use laboratory/facility.
The Radiation Safety Office is responsible for performing, or having performed, all portable radiation measuring instrument calibrations. The Authorized User is responsible for performing operability, and when appropriate, efficiency checks, on the equipment in their facilities/laboratories. All radiation measuring equipment must be calibrated annually.
GM and beta scintillation detectors are useful for monitoring medium-to-high energy beta radiation. These detectors are not capable of detecting H-3 due to its low beta energy. Liquid scintillation counters are used to monitor H-3. Gamma scintillation detectors are used to detect low-to-high energy gamma and x-rays.
| Radionuclide | Radioactive half-life | Radiation type, energy level | Exposure rate at 1 foot from 1 mCi point source without shield | Shielding requirement |
|---|---|---|---|---|
| H-3 | 12.3 years | Beta, low | Low | None |
| C-14 | 5730 years | Beta, medium | Low | None |
| P-32 | 14.3 days | Beta, high | 300 mrad/hr | Plexiglas/plastic |
| S-35 | 87 days | Beta, medium | Low | None |
| Ca-45 | 162.7 days | Beta, medium | Low | None |
| Sc-46 | 83.8 days | Gamma, high | 12 mR/hr | Lead |
| Cr-51 | 27.7 days | Gamma, medium | 0.2 mR/hr | Lead |
| Fe-59 | 44.5 days | Gamma, high | 7 mR/hr | Lead |
| I-125 | 60 days | Gamma & xray, low | 0.8 mR/hr | Lead, leaded glass or plastic |
| I-131 | 8.3 days | Gamma, medium | 2.4 mR/hr | lead |
| Detector Type | Detects Alpha Radiation | Detects Beta Radiation | Detects X-Ray and Gamma Radiation | Radionuclides to Detect | Portability |
|---|---|---|---|---|---|
| GM, metal cylinder | No | Yes | Yes | P-32, Cr-51, Sc-46, I-131 | Yes |
| GM, pancake | Yes | Yes | Yes | Most RAMs used at UNR except H-3 | Yes |
| GM, Thin end | Yes | Yes | Yes | Most RAMs used at UNR except H-3 | Yes |
| Beta scintillation | No | Yes | No | C-14, P-32, P-33, S-35, Ca-45 | Yes |
| Beta-gamma scintillation | No | Yes | Yes | C-14, P-32, P-33, S-35, Ca-45, Sc- 46, Cr-51, I-125, I-131 | Yes |
| Ion chamber | No | No | Yes | Gamma (beta if equipped) exposure rate | Yes |
| Liquid scintillation analyzer | Yes | Yes | Yes | All RAM used at UNR including H-3 | Fixed |
| Gas Proportional counter | Yes | Yes | Yes | All RAM used at UNR | Fixed |